JPS63199683A - Ink film for electrical thermal transfer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is directed to an electrically conductive thermal transfer ink film for use in an electrically conductive thermal transfer printer.

[Conventional technology]

In recent years, thermal transfer recording has been used in many fields such as facsimiles, computer terminals, recorders, and printers because it has the advantages of being non-impact, noiseless, maintenance-free, low cost, and capable of color printing. In particular, the current-carrying type has a thermal energy disadvantage compared to general thermal transfer recording, so it is said to be able to be made smaller, lighter, faster, and full-color.

Generally, the ink of a thermal transfer recording film used in a thermal transfer printer must undergo a clear phase change from solid to liquid to solid in a short period of time during thermal transfer, and must quickly transfer from the support layer to the receiving paper. For this reason, conventional ink films for thermal transfer use inks in which the main component of the ink composition is wax, in which a coloring agent is dispersed and synthetic resins and plasticizers are added.

[Problem that the invention seeks to solve]

As mentioned above, conventional thermal transfer ink films have problems such as adhesion between the ink and the transfer paper during printing, and
The 14II Fit force with A91 was controlled by synthetic resins and plasticizers in the ink components. Particularly when performing full-color printing using area gradation with current-carrying type ink, the cohesive force during melting can be improved without increasing the synthetic resin component in the ink, resulting in a clear printed image with good dot reproducibility. With the support base? The separation becomes poor and smooth halftone reproduction cannot be obtained.

The present invention is intended to solve this problem, and its purpose is to provide a full-color electrothermal transfer ink with a large cohesive force and contact force to achieve high printing quality, and to provide a support layer for the thermal transfer. The purpose of this invention is to provide an ink film for electrothermal transfer that solves the conflicting characteristics of poor release properties and takes advantage of the advantages of ink.

[Means for solving problems]

In order to solve the above problem, the present invention implements the following configuration.
do.

In other words, support! This is an ink film for electrical thermal transfer in which an acrylic resin III Fit layer is provided between the J layer and the wax-based ink layer.
An acrylic resin having a critical surface tension smaller than that of the wax-based ink and support layer material τ used in the Jll ink film is used for delamination.

The support layer is preferably one that has heat resistance, mechanical strength, and high smoothness. The material is a resin film such as polyimide or polyethylene terephthalate, and the thickness is 1~
The thickness is preferably 15 μm.

As the binder for the wax-based ink layer, paraffin wax, microcrystalline wax, carnauba wax, oxidized wax, Fischer-Tropsch wax, etc. are used, and the synthetic resinous acid component contained in this wax-based ink layer is ethylene. - Acetic acid beer copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer (11 substances exhibiting thermal diffusivity such as coalescence, or a mixture thereof are used.

Furthermore, since it is an energized type, a resistive layer is provided on the opposite side to the support layer of the wax-based ink layer. As a component of this resistance layer, gflE carbon black is preferably dispersed in a binder such as polyester, polyurethane, or nitrocellulose.

[Effect]

The required properties of the release layer component of the present invention are at least
The separation must be selected so that the adhesive force between the separation layer and the ink is smaller than the adhesive force between the ink layer and the interprinted paper. Therefore, the present inventors focused on the critical surface tension and Liquid ink and support layer when melted and their? tli! + Critical surface tension 10 to 25 dyn/cm (54
dyn liquid)? The decision was made to remove the material. Specifically, by using acrylic resin, mechanical strength and transparency can be sufficiently improved. Also, 9111'1
The coating thickness should be 0.05~ to minimize the heat loss of iFI.
By setting the diameter to 0.1 μm, it is possible to obtain an ink film for electrical thermal transfer that is suitable for full-color printing and has good dot reproducibility and halftone reproducibility by taking advantage of the properties of wax-based ink, which are high cohesive force and high bonding force. Hereinafter, the present invention will be specifically explained with reference to Examples.

〔Example〕

(1) of the ink film for electrical thermal transfer with a release layer of the present invention
The structure is shown in Figure 1.

11 is the resistance layer, 12 is the support t11 layer, 13 is ? FiII
Layer 14 is a wax-based ink layer.

Polyethylene Preftanot was used as the support layer, and the resistance layer composition, resistance layer coating thickness, wax-based ink A4 composition, wax-based ink layer coating thickness, and support T7 layer thickness were set as constant conditions. Select several types of delamination materials? Su has produced an ink film for residential electrical thermal transfer.

1) Support layer material and thickness Polyethylene terephthane) Ou m FX 2) Resistance layer composition Furnace black; 20 parts by weight Butyral resin; 70 parts Polyurethane; 10 parts 3) Resistance layer coating In the composition of 2) Butyral resin, polyurethane and toluene/MEK=1/l binary solvent at a solid content concentration of 30%, and furnace black is uniformly dispersed in this solution using a ball mill. The thus obtained 11 (anti-layer coating solution) was coated with a solvent method using a wire bar, and 12
After drying, it was coated to a thickness of 3.6 μm.

4) Ink layer composition Pigment; 20I'11 parts paraffin wax; 20 parts oxidized wax; 40 parts ethylene/vinyl acetate copolymer: 20 parts stearic acid;
3 parts 5) Ink layer coating The composition of 4) was kneaded and dispersed by preliminary dispersion using a Nigoo machine and dispersion using a three-roll mill. The ink thus obtained was applied to a thickness of 3 μm using a hot melt gravure roll.

Example 1 - 1) Separation layer material f: [Primal AC-33 Nippon Acrylic Chemical OJ Surface tension 27.6 dyn/cm 20@C solid content concentration 46.5% 2) 2' inner layer coating l) The material for the cultivation layer was diluted with ion-exchanged water to a solid content of 5% and then dried using a wire bar using the solvent method for about 20 minutes before drying.
μm thickness, dry H! Approximately 0.1 tzml of the solution was then applied.

Example 2-1) III Delamination material Bon=! -To 5T-372 Dainippon Ink Kagaku Nikyu Co., Ltd. Surface tension 1G, 8dyn/cm 2 (3"C solid denominator If 40% 2 ) 71m Release layer material of 1 K rim was ionized and solidified with water. diluted to a concentration of 5%, and dried using a wire bar using the solvent method to approximately 2μ
After drying, the coating was applied to a thickness of about 0.1 μm.

Example 3-1)? 1i11 Garlic material 1 Siren A-14-1 L1 Junyaku Co., Ltd. Surface tension 32.7 dyn/cm 20°C161 type 6Ia' 40% 2) 911 layer coating ゛l) completion separation The solid content of the layer material is 5% cJ with ion-exchanged water.
The solution was diluted to 100% and coated using a wire bar by a solvent method to a thickness of about 2 μm before drying and about 0.1 μm after drying].

Comparative Example 1-III No 111 layer was provided, and a three-layer structure consisting of an ink layer, a supporting layer, and an anti-layer was used.

Using the quick films for electrical thermal transfer of the present invention obtained in Examples 1 to 3 and Comparative Example 1, full-color prints and 16 magenta gradations were printed on perspiration paper using a current-carrying head.

1) Current-carrying head dot pitch: 6 dots/mm Line pitch: G dots/mm Head needle diameter: 60 μm 2) Driving applied voltage: 30 V Pulse width modulation: 50 μscc to 1.0 mm SCC full color printing has 32 gradations 3) Full color printing Using the resulting color silver halide copy Jτ as the original, after color separation using a color scanner, it was converted into various signals of 32 gradations, and a full color print was made.

Prints using the ink film for electrical thermal transfer of the present invention yielded beautiful color images with gradation that were extremely close to the original images.

4) As a result of 16-gradation printing, select magenta, whose gradation evaluation is the most difficult to understand among yellow, magenta, and cyan, and use the monochrome magenta color signal of 16-gradation straight line r as an input signal. Perform gradation printing and use a densitometer to print 0D (OPLical)
DcnciLy) values were measured for each gradation, one curve was drawn and compared with the input signal. The cold weather is shown in Figures 3 and 4. Each measured value was plotted with 16 gradations on the horizontal axis and the OD value on the vertical axis. 3. Examples 1 to 3 all resulted in curves close to a straight line, which is manually applied (iT), and were clearly reproduced from low density to high density. I can see that it is being done.

〔Effect of the invention〕

As explained above, the peelable ink film for electrical thermal transfer of the present invention can fully exhibit the characteristics of ink with high cohesive force and contact force in area gradation full color printing compared to conventional ink films for electrical thermal transfer. To obtain good dot reproducibility and smooth halftone reproduction, to suppress jumps in transfer density or gradation that are common in area gradation full color printing, and to provide a beautiful color image that approaches density gradation full color printing.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the #1 ink film for residential electrical thermal transfer of the present invention. FIG. 2 is an explanatory diagram of a conventional ink film for electrical thermal transfer. 3 and 4 are r curve diagrams consisting of gradations and OD values of Examples 1 to 3 and Comparative Example 1. 14 in 7 rinth' factor 2nd figure ------------* column I 1 x --------x Hisha history column A 1st floor Δn 3rd factor @-=--- -e La [Force 1E A row 2 Mu--1--
--^ 〃 3 Figure 4

Claims (2)

[Claims] (1) In an areal gradation full-color electrical thermal transfer ink film having a wax-based ink layer, a support layer, and a resistance layer, there is a release layer between at least the ink layer and the support layer, and the criticality of the release agent used in the release layer. An ink film for electrical thermal transfer, characterized in that its surface tension is less than or equal to the critical surface tension of an ink layer and a support layer. (2) The ink film for electrical thermal transfer according to claim 1, wherein the release agent used in the release layer is an acrylic resin.